The efficacy of convalescent plasma for coronavirus disease 2019 (COVID-19) is unclear. Although most randomized controlled trials have shown negative results, uncontrolled studies have suggested that the antibody content could influence patient outcomes. We conducted an open-label, randomized controlled trial of convalescent plasma for adults with COVID-19 receiving oxygen within 12 d of respiratory symptom onset (NCT04348656). Patients were allocated 2:1 to 500 ml of convalescent plasma or standard of care. The composite primary outcome was intubation or death by 30 d. Exploratory analyses of the effect of convalescent plasma antibodies on the primary outcome was assessed by logistic regression. The trial was terminated at 78% of planned enrollment after meeting stopping criteria for futility. In total, 940 patients were randomized, and 921 patients were included in the intention-to-treat analysis. Intubation or death occurred in 199/614 (32.4%) patients in the convalescent plasma arm and 86/307 (28.0%) patients in the standard of care arm—relative risk (RR) = 1.16 (95% confidence interval (CI) 0.94–1.43, P = 0.18). Patients in the convalescent plasma arm had more serious adverse events (33.4% versus 26.4%; RR = 1.27, 95% CI 1.02–1.57, P = 0.034). The antibody content significantly modulated the therapeutic effect of convalescent plasma. In multivariate analysis, each standardized log increase in neutralization or antibody-dependent cellular cytotoxicity independently reduced the potential harmful effect of plasma (odds ratio (OR) = 0.74, 95% CI 0.57–0.95 and OR = 0.66, 95% CI 0.50–0.87, respectively), whereas IgG against the full transmembrane spike protein increased it (OR = 1.53, 95% CI 1.14–2.05). Convalescent plasma did not reduce the risk of intubation or death at 30 d in hospitalized patients with COVID-19. Transfusion of convalescent plasma with unfavorable antibody profiles could be associated with worse clinical outcomes compared to standard care.

The expression of angiotensin-I converting enzyme (ACE; EC 3.4.15.1) in human circulating mononuclear cells was studied. T-lymphocytes contained the highest level of enzyme, approx. 28 times more per cell than monocytes. No activity was detected in B-lymphocytes. ACE was present mainly in the microsomal fraction, where it was found to be the major membrane-bound bradykinin-inactivating enzyme. An mRNA for ACE was detected and characterized after reverse transcription and amplification by PCR in T-lymphocytes and several T-cell leukaemia cell lines. We have previously observed that the interindividual variability in the levels of ACE in plasma is, in part, genetically determined and influenced by an insertion/deletion polymorphism of the ACE gene. To investigate the mechanisms involved in the regulation of ACE biosynthesis, the ACE levels of T-lymphocytes from 35 healthy subjects having different ACE genotypes were studied. These levels varied widely between individuals but were highly reproducible and influenced by the polymorphism of the ACE gene. T-lymphocyte levels of ACE were significantly higher in subjects who were homozygote for the deletion than in the other subjects. These results show that ACE is expressed in T-lymphocytes and indicate that the level of ACE expression in cells synthesizing the enzyme is genetically determined.

In patients with STEMI undergoing primary PCI by operators experienced in both access sites, the radial approach was associated with significantly lower incidence of major bleeding and access site complications and superior net clinical benefit. These findings support the use of the radial approach in primary PCI as first choice after proper training. (Trial Comparing Radial and Femoral Approach in Primary Percutaneous Coronary Intervention [PCI] [STEMI-RADIAL]; NCT01136187).

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These results extend our previous findings and indicate that plasma ACE level may be a risk factor for MI, independent of the ACE I/D polymorphism.

BackgroundIncidence of radial artery occclusions (RAO) and ulnar artery occclusions (UAO) in coronary procedures, factors predisposing to forearm arteries occlusion, and the benefit of anticoaggulation vary significantly in existing literature. We sought to determine the incidence of RAO/UAO and the impact of anticoagulation intensity.Methods and ResultsMeta‐analysis of 112 studies assessing RAO and/or UAO (N=46 631) were included. Overall, there was no difference between crude RAO and UAO rates (5.2%; 95% confidence interval [CI], 4.4–6.0 versus 4.0%; 95% CI, 2.8–5.8; P=0.171). The early occlusion rate (in‐hospital or within 7 days after procedure) was higher than the late occlusion rate. The detection rate of occlusion was higher with vascular ultrasonography compared with clinical evaluation only. Low‐dose heparin was associated with a significantly higher RAO rate compared with high‐dose heparin (7.2%; 95% CI, 5.5–9.4 versus 4.3%; 95% CI, 3.5–5.3; Q=8.81; P=0.003). Early occlusions in low‐dose heparin cohorts mounted at 8.0% (95% CI, 6.1–10.6). The RAO rate was higher after diagnostic angiographies compared with coronary interventions, presumably attributed to the higher intensity of anticoagulation in the latter group. Hemostatic techniques (patent versus nonpatent hemostasis), geography (US versus non‐US cohorts) and sheath size did not impact on vessel patency.ConclusionsRAO and UAO occur with similar frequency and in the order of 7% to 8% when evaluated early by vascular ultrasonography following coronary procedures. More‐intensive anticoagulation is protective. Late recanalization occurs in a substantial minority of patients.

TRA is already widely used across the world. Diagnostic and guiding-catheters used for TRA remain similar to those used for traditional femoral approach, suggesting that specialized radial catheters are not frequently used. However, there is substantial variation in practice as it relates to specific aspects of TRA, suggesting that more data are needed to determine the optimal strategy to facilitate TRA and optimize radial artery patency after catheterization.

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